I, too, have no microphone signal (only static) on my Librem13v2 (see recent thread on the same topic here).
Here’s a photo of the same connector, in my laptop:
The connector has sockets for two wires:
- ground
- signal and power
As explained on a Purism blogpost, for an earlier model of the Librem.
This arrangement on our laptops ought to work, assuming:
- the wire leading into the blob of silicone actually connects to something (I would assume ground), and
- the manufacturing plant worker didn’t get the ground and signal sockets or wires confused!
I haven’t heard back from customer service yet. I’ll update this post when I do.